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| Titel |
Bromine measurements in ozone depleted air over the Arctic Ocean |
| VerfasserIn |
J. A. Neuman, J. B. Nowak, L. G. Huey, J. B. Burkholder, J. E. Dibb, J. S. Holloway, J. Liao, J. Peischl, J. M. Roberts, T. B. Ryerson, E. Scheuer, H. Stärk, R. E. Stickel, D. J. Tanner, A. Weinheimer |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 14 ; Nr. 10, no. 14 (2010-07-16), S.6503-6514 |
| Datensatznummer |
250008632
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| Publikation (Nr.) |
 copernicus.org/acp-10-6503-2010.pdf |
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| Zusammenfassung |
| In situ measurements of ozone, photochemically active bromine compounds, and
other trace gases over the Arctic Ocean in April 2008 are used to examine
the chemistry and geographical extent of ozone depletion in the arctic
marine boundary layer (MBL). Data were obtained from the NOAA WP-3D aircraft
during the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate
(ARCPAC) study and the NASA DC-8 aircraft during the Arctic Research of the
Composition of the Troposphere from Aircraft and Satellites (ARCTAS) study.
Fast (1 s) and sensitive (detection limits at the low pptv level)
measurements of BrCl and BrO were obtained from three different chemical
ionization mass spectrometer (CIMS) instruments, and soluble bromide was
measured with a mist chamber. The CIMS instruments also detected Br2.
Subsequent laboratory studies showed that HOBr rapidly converts to Br2
on the Teflon instrument inlets. This detected Br2 is identified as
active bromine and represents a lower limit of the sum HOBr + Br2. The
measured active bromine is shown to likely be HOBr during daytime flights in
the arctic. In the MBL over the Arctic Ocean, soluble bromide and active
bromine were consistently elevated and ozone was depleted. Ozone depletion
and active bromine enhancement were confined to the MBL that was capped by a
temperature inversion at 200–500 m altitude. In ozone-depleted air, BrO
rarely exceeded 10 pptv and was always substantially lower than soluble
bromide that was as high as 40 pptv. BrCl was rarely enhanced above the
2 pptv detection limit, either in the MBL, over Alaska, or in the arctic
free troposphere. |
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